adrenergic pharma

Question 1

enzyme responsible for L-DOPA production

Answer 1

Tyrosine hydroxylase (negative feedback inhibition by noradrenaline)

Question 2

Enzyme responsible for conversion of dopamine into noradrenaline

Answer 2

dopamine beta hydroxylase, found at synaptic vesicles

Question 3

Enzyme responsible for converstion of noradrenaline –> adrenaline

Answer 3

phenylethanolamine-N-methyltransferase (PNMT), found in the adrenal medulla

Question 4

Protein involved in transport of noradrenaline back into presynaptic neuron from synaptic cleft

Answer 4

NET (norepinephrine transporter)

Question 5

Protein involved in transport of noradrenaline back into presynaptic vesicles

Answer 5

VMAT (vesicular monoamine transporter)

Question 6

Which receptor mediates autoinhibition of noradrenaline release?

Answer 6

presynaptic alpha2

Question 7

Enzyme that mediates the breakdown of endogenous and exogenous catecholamines

Answer 7

monoamine oxidase (MAO) – COMT is the plasma equivalent (catechol-O-methyltransferase)

Question 8

What type of receptors are adrenergic receptors?

Answer 8

GPCRs

Question 9

Effects of alpha1 activation

Answer 9

VSMC vasoconstriction leading to higher blood pressure. Can lead to reflex bradycardia (low HR in response to high BP)

Question 10

Effect of alpha2 activation

Answer 10

autoinhibition of noradrenaline release, also inhibits insulin secretion by pancreatic islet cells

Question 11

Effect of beta1 activation

Answer 11

Increased cardiac output (rate and force of cardiac contraction), also increase in renin release from juxtaglomerular kidney cells (catalyses angiotensinogen –> AT1, ACE catalyses AT1 –> AT2, potent vasoconstrictor, also induces release of aldosterone from adrenal glands –> Na+ and H2O retention –> increased blood volume, increased blood pressure)

Question 12

Effect of beta2 activation

Answer 12

Relaxation of smooth muscle cells (broncho/vasodilation, relaxation of uterine muscles)

Question 13

beta2 agonist for asthma treatment

Answer 13

salbutamol –> bronchodilation

Question 14

noradrenergic drug for treatment of cardiac arrest/anaphylaxis

Answer 14

epinephrine

Question 15

alpha2 partial agonist

Answer 15

clonidine, decreases sympathetic activity via autoinhibition of adrenergic neurons

Question 16

non-selectictive beta antagonist

Answer 16

propanolol, mainly used as a hypertensive for its anti-beta1 effects

Question 17

inhibitor of tyrosine hydroxylase, used in the treatment of adrenaline-secreting adrenal tumours

Answer 17

alpha-methyl-P-tyrosine, prevents first step of catecholamine synthesis, decreased NA/A levels so less sympathetic activity

Question 18

VMAT inhibitor, used to treat hypertension/mood disorders

Answer 18

reserpine, prevents noradrenaline vesicular uptake, therefore NA is depleted by MAOs

Question 19

drugs that are structurally similar to NA and are therefore taken up by NET/VMAT, also have weak inhibitory activity against MAOs, promote adrenergic activity without neuron depolarisation

Answer 19

amphetamines

Question 20

drug that inhibits NET, leading to accumulation of neurotransmitters in the synaptic cleft –> upregulation of sympathetic activity

Answer 20

cocaine

Question 21

MAO inhibitor, used as an anti-depressant

Answer 21

moclobemide, increases the availability of neurotransmitters by preventing their degradation by MAO

Question 22

hormone who’s release is stimulated by AGII and causes increase Na+ and water retention, increasing blood volume

Answer 22

aldosterone

Question 23

potent beta-selective agonist

Answer 23

isoprenaline